Scissors



March 8 1927 1,620,225

M. PARKER scxssoas Fi led Aug. 20. 1921 A TTORNE Y5 Patented Mar. 8, 1927.

MORGAN PARKER, on NEW YORK, N. Y.

scrssores.

Application filed August 20, 1921.

This invention relates to scissors having replaceable blades or cutting edges. Scissors and shears which are in constant use must be continually resharpened. This is not only expensive and time-consuming, especially if the blades are ground to a properly serrated cutting edge, as for barber's shears, but after a time the grinding wears the blades to such a condition that the scissors must be discarded. In. some instancestoo it may be diflicult to secure the services of a skillful grinder, so that the SClSSOI'S must either be poorly ground or be used when too dull for ellicient cutting. Furtheri'nore, the blades of the common type of scissors should be made of high grade cutlery steel throughout if they are to present and retain a keen cutting edge after each grindin This is-expensive and involves drop-forging difliculties.

It was early recognized that a two-part blade would solve some of these dilliculties. A tool steel cutting blade welded or mechanically'attached to a softer metal shank simplifies the drop-forging problem and makes a cheaper instrument, but the resharpening problem still persists. Such blades when mechanically secured to the shank, are comparativ-ely heavy, are ground to shape like any scissor blade, and are too costly to be discarded rather than resharpened. The welded blade becomes, of course, an integral part 01" the shank, and the completed instrument therefore presents'no advantages over scissors having blades of tool steel throughout. The ideal scissors would comprise light, cheap cutting parts of high grade steel, removably attached to shanks of softer metal, and so inexpensive that they might be thrown away when dull, and replaced by others at less than the cost of sharpening or grinding. It is broadly the object-of this invention to produce such scissors.

The cutting edges of scissors commonly define a helical or three dimensional curve, the curvature depending upon the type of scissors and the work for which they are designed. To grind this curve into each blade would involve a prohibitive expense where the blade is to be discarded after the first dulling, and I therefore make my blade straight, but so flexible as to'be conformable to any curve or twist normally defined by the permanent shank on which the blade is mounted. My blade is, in fact, a specially shaped steel Wire of uniform cross-section Serial No.' 493,934.

which can be drawn or rolled and cut to length.

It is important that the blade contact with the shank to the very tip of the scissors thus preventing the admission of lint or dirt or the catching of a hair or thread. Now a blade flexible enough to conform to any normal curve of the shank must be relatively light. I therefore provide means for positively holding the blade in contact with the shank throughout its length, this contact at no point depending upon the rigidity or spring pressure of the blade itself. I also so shape the blade and shank that the passage of a hair orthread between them at their co-terminus is impossible. V 1

In order to simplify the problem of attaching the blade to and detaching it from the shank I provide a structure in-which the blade may be freely moved to and from its supporting shank when the scissors are wide open, but in which the blade is securely locked against removal when the opposing shanks are in any other position.

In the accompanying drawings I have illustrated two advantageous embodiments of my invention, a study of which willmake clear the principles involved.

' In these drawings Fig; 1 is an elevation of a pair. of scissors equipped with removable blades in accordance with this invention; Fig. 2 is an enlarged section through one of the shanks of such scissors showing the removable blade in position; Fig. 3 is a per- 'sp'ective view of a section of the removable blade; Fig. 4 is an enlarged fragmentary view showing the means for locking the blade against longitudinal displacement; Fig. 5 is a section taken on line 55 of Fig. 4:; Fig. 6 is a section similar to Fig. 2, but showing a modified form of the invention; and. Fig. 7 is av perspective view of the modified form of blade shown in Fig. 6. In Figures 2,3, 5, 6 and 7 the blade is shown enlarged many times for the purpose of more clearly illustrating its relation to the shank. It therefore appears'much heavier than it actually is. v

The scissors shown in Fig. 1 of the drawings are of the type employed by barbers, but the invention is obviously applicable to scissor-s or shears of any type. These scissors comprise shanksl pivoted together by means of the ordinary king pin 2. Each of these shanks is provided in its inner face adjacent its operative edge with a-longitushown in the drawing.

dinal groove 3 extending from the tip of the shank to a point adjacent that part defined by the companion shank when the scissors are in their wide open position. This groove is arcuate in cross section, as shown most clearly in Fig. 2. The inner end of each of these grooves 3 terminates in a cavity 4 formed by cutting away a part of the overhanging metal. This cavity is clearly shown in Fig. 5 and its method of formation readily understood by comparing this figure with Fig. 2. In plan this cavity 4 is V-shaped with the point of the V extending toward the lower or heavy edge of the shank, as shown in Fig. 4. The purpose for this will be described later.

The blade 5 clearly shown in Figs. 2 and 3 comprises a strip of drawn steel resembling roughly in cross section the arabic numeral 7. This blade comprises a shear face 6 terminating in a cutting edge 7 and having depending from the other side thereof an arcuate flange 8. At that end of the blade designed to contact with the inner end of the groove 3 the arcuate flange 8 is flattened until for a short distance, as indicated at 9, that part of it is almost but not quite in the plane of face 6, as shown in Fig. 5. This upwardly bent portion 9 of the flange 8 is also cut to a V-shape, as shown'in Fig. 4. The blade is universally flexible and can be bent not only sidewise but in the plane of its shear face.

To place the blade in position upon its shank the scissorsmust first be opened to the position of greatest width, as shown in Fig. 1. The blade is readily located longitudinally of the shank by placing the V- shaped projection 9 within the V-shaped cavity 4. At the same time the lower edge of flange 8 is laid along the upper edge of groove 3 and the blade then swung or rolled into position. The shank is formed so that when the blade is in position the face portion 6 thereof lies almost, but not quite within the plane of the inner face of the shank. In order to allow clearance for the cutting edge 7, the face 6 of the blade makes avery slight angle with the inner face of the shank, but this angle is too slight to be Beyond the cutting edge 7 the blade extends outwardly and covers the edge of the shank so that the line of separation between shank and blade is on the outer face of the shank and not on its operative edge. hen in closed position there is a slight clearance 10 between the bottom of groove 3 and the lower edge of flange 8, as shown in Figs. 2 and 3. Were it not for this, the dust collecting at the bottom of this groove would prevent accurate seating ofthe blade. During normal use the blade is held in position by the mutual opposition of the shanks. This constitutesa simple and efiective locking means which adds to the facility with which the blade can be attached and detached. To remove the blade when dulled it is only necessary to reverse the operations employed in positioning it. As soon as the scissors are open to their Widest position the blade may be easily rolled out of the groove in the shank and a new one inserted.

In scissors of this type the only displacement of the blade possible during ordinary use would be one in a longitudinal direction. It is one of the functions of parts 4 and 9 to prevent this. As will be clear from a study of Fig. 5, the part 9 contacts with the wall of the cavity 4; when the blade is in cutting position and thus makes any outward movement of the blade impossible. By slightly depressing the end of part 9 below the plane of the inner face of the shank, danger of interference with the closing of the scissors is obviated, even after considerable wear. Moreover, as the scissors close the other-shank tends to slide up over the blade at 9 and force it into final position.

In the modification shown in Figs. 6 and 7, the arcuate groove 3 is replaced by a cylindrical groove 12 and the arcuate flange 8 by cylindrical bead 13 flattened on one side at 14 to permit of introduction within the groove 12, as shown in Fig. 6. In order to prevent longitudinal movement when this type of blade is used, the shank is provided with an upstanding dowel pin 15 positioned at a point corresponding to that occupied by the cavity 4 in the other form and cooperating with a hole 16 punched in the face of the blade.

The blades described above are made from the best tool steel drawn or rolled and tempered. They are very flexible and will spring at right angles to the cutting edge, or longitudinally in any direction either laterally or edgewise through 360, as well as helieally, so that they are conformable to whatever curve the shank may be made. This means that the blades can be made in straight wire form, hardened and ground to a straight cutting edge while in length and cut off to size, without specially grinding them to the shape and twist of the shank. They are easily and quickly placed in position upon their shanks and when the scissors are in ordinary operation are locked in place by their mutual opposition without the need of any other securing device. They are also positively held and supported by the shank throughout theirentire length from the (31% treme co-terminus of blade and shank to their inner ends, so that no dependence need be placed upon the rigidity or resiliency of the blade to prevent separation from the shank. This is very important and obviates any possibility of the blade springing from the shank at the tip and forming an open ing which is likely to catch upon hair or ltll) llll lift) thread. The overhang of the cutting edge also places the longitudinal dividing line between blade and shank in such a position that nothing is likely to be caught in it.

These blades may be so cheaply made'that they can be used and when dull replaced by another for less than the present cost of regrinding. Scissors equipped with such blades possess all the advantages of ordinary I scissors with the added advantage that they may be kept perpetually sharp without the expense and other disadvantages incident upon repeated grinding.

I claim: i

1. A blade adapted to be mounted on a scissors shank, having a cross-section of continuous uniform dimensions throughout substantially its entire length, and being universally flexible.

, 2. A blade adapted to be mounted on a scissors shank and comprising a section of a continuous rolled or drawn strip having its longitudinal edges parallel and being flexible in the direction defined by the cut ting movement throughout substantially its entire length.

3. Scissors comprising the. combination of a shank having a longitudinal grove, and a blade of substantially uniform section throughout its length seated in said groove and being flexiblein the direction defined by the cutting movement of the scissors.

a. A blade designed to be mounted on a scissors shank, universally flexible throughout its length to conform to any curve normally defined by the shank.

5. A blade designed to be mounted on a scissors shank, having a normally straight cutting edge and shear face, flexible in the plane of its shear face throughout itslength.

t. Scissors comprising the combination of a. shank having a curved operative edge, a blade flexible transverselyin any direction mounted on the shank, and means for flexing the blade to conform to thecurve of the edge.

7. Scissors comprising the combination of a shank having a curved operative edge, a blade flexible transversely in any direction mounted on the shank, and means for positively holding the blade in contact with the shank throughout the entire length of the blade.

8. Scissors comprising the combination of a shank having a curved operative edge, a groove in the shank extending along the operative edge for the entire length of that edge and following the curvature thereof, and a normally straight blade flexible transversely in any direction throughout its length seated in the groove and conforming to its curvature.

9. Scissors comprising the combination of a pair of shanks having curved operative edges, a groove in a shank extending along the operative edge for the: entire length of that edge and following the curvature thereof, and anormally straight blade flexible transversely in any direction throughout its length seated in the groove and conforming to its curvature, the normal opposition of the other shank holding the blade in the groove against lateral displacement.

10. Scissors comprising the combination of a. pair Ofshanks having curved operative edges, a groove in a shank extending along the operative edge for the entire length of that edge and following the curvature thereof, a normally straight blade flexible transversely in any direction throughout its length seated in the groove and conforming to its curvature, the normal opposition of the other shank holding the blade in the groove against lateral displacement, and means for holding the blade against longitudinal dis placen'ient.

11. Scissors comprising the combination of a pair of shanks and a removable blade locked in position on a shank when the shanks are in mutual opposition during ordinary use of the scissors and unlocked when the scissors are wide open.

12. Scissors comprising the combination of a pair of shanks and removable blades locked in position upon the shanks when the blades are in mutual opposition during ordinary use ofthe scissors and unlocked when the scissors are wide open.

13. Scissors comprising the combination of a pair of shanks, a longitudinal groove in a shank, and a blade movable into the groove when the shank-s are in wide open position by a movement toward the shear face of the shank but held against retractile movement'by the normal opposition of the shanks.

14. Scissors comprising the combination of apair of Sl1f1I1 S, fl longitudinal groove in a shank, a blade movable into the groove when the shanks are in wide open position by a movement toward the. shear face of the shankbut held against retractile movement by the normal opposition of the shanks, and

means holding the blade against longitudinal movement so that except when the shanks are in wide open position the blade is locked against removal. 7

15. Scissors comprising the combination of a pair of shanks, a longitudinal undercut groove in the inner face of a shank, and a blade having a longitudinal flange movable transversely into the groove when the shanks are in wide open position but held against retractile movement by the normal oppositlon of the shanks.

16. Scissors comprising the combination of a pair of shanks, a longitudinal groove in the inner face of a shank curved in transverse section, and a blade having a depending flange curved to fit the groove in the shank and designed to be seated therein by a swing .ing movement when the shanks are in wide open position, the normal opposition of the shanks preventing a: retractile swinging movement of the blade.

17. Scissors comprising the combination of a pair of shanks, a longitudinal groove in the inner face of a shank, a blade slidable transversely into the groove and seated a swinging movement, the normal opposition of the other shank preventing a retractile swinging movement of the blade, and means for locking the blade against longitudlnal movement.

18. In scissors having a removable blade, the combination of a shank, a longitudinal groove in the shank arcuate in transverse section, and a blade comprising a cutting edge and a depending arcuate flange designed to be seated within the arcuate groove in the shank.

19. In scissors having a removable blade, the combination of a shank, a longitudinal groove in the shank arcuate in transverse section, and a blade comprising a cutting edge and a depending arcuate flange designed to be seated within the arcuate groove of the shank, the relation of the parts permitting positioning of the blade by means of a transverse swinging movement.

20. In scissors having a removable blade, the combination of a shank, a longitudinal groove in the shank, a cavity inthe shank communicating with said groove, and a blade comprising a cutting edge and a depending flange designed to be swung transversely into said longitudinal groove, a portion of said flange being shaped to enter the said cavity and lock the blade against longitudinal movement.

21. In scissors having a removable blade, the combination of a shank, a longitudinal groove in the shank terminating in a cavity, and a blade comprising a cutting edge and a depending flange designed to be swung transversely into said longitudinal groove, one end of said flange being shaped to enter the said cavity and lock the blade against longitudinal movement.

22. In scissors having removable blades, the combination of a shank, a longitudinal groove circular in cross section in the shank longitudinally open on one side, and a blade designed to be rotatably inserted through the open side in the circular groove in the shank.

23. In scissors having a removable blade, means for mechanically securing the blade to its supporting shank at their co-terminus and obstructing the admission of any foreign body between the blade and shank.

24. In a removable blade scissor, the combination with the scissor shank of a removable blade having a co-terminus with the shank, and means for mechanically securing the blade to the shank at their co-terminus and obstructing the passage of a foreign body between the blade and shank at their co-terminus.

25. Removable blade scissors comprising the combination of a shank, a longitudinal groove in the shank, anda blade having a cutting edge and a flange seated in the groove, the blade terminating at its outer end with the shank, the flange obstructing the passage of a hair or thread between the blade and shank at their co-terminus.

26. Scissors comprising the combination of a pair of shanks having longitudinally extending recesses therein, and a universally flexible blade fitting into the recesses in each shank and held in operative cutting position by the normal opposition of the shanks.

27. Scissors comprising the combination of a pair of shanks havinglongitudinally extending recesses therein, a universally flexible blade fitted into the recesses in each shank and held in operative cutting position by the normal opposition of the shanks, and means for holding the blades against longitudinal displacement.

In testimony whereof I affix my signature.

MORGAN PARKER. 

